Self-contained evaporative air conditioner system

ABSTRACT

A self-contained evaporative air conditioner system includes a housing having a central chamber, a lower chamber, and an upper chamber; a heat exchanger positioned in the central chamber; an air nozzle and a water nozzle for creating a mist of water droplets suspended in air in the lower chamber; an ambient air vent for introducing non-pressurized ambient air to the lower chamber; a vacuum assembly for creating a partial vacuum in the upper chamber to draw the mist and ambient air through the heat exchanger to remove heat from the heat exchanger through evaporative cooling; a return air vent for receiving air to be conditioned; and a fan for drawing air from the return air vent through the heat exchanger to remove heat from the air without permitting the air to mix with the mist and ambient air drawn through the heat exchanger.

BACKGROUND

The present invention relates to air conditioning systems. Moreparticularly, the invention relates to a self-contained evaporative typeair conditioning system.

Most air conditioning systems use vapor-compression or absorptionrefrigeration cycles. Although such air conditioning systems areeffective at cooling, they use a great deal of energy.

Evaporative type air conditioning systems cool air, liquids, or othermediums with much less energy than vapor-compression and absorptionrefrigeration systems. Evaporative cooling works by employing water'slarge enthalpy of vaporization. The temperature of air, especially whendry, can be dropped significantly through phase transition of water froma liquid to a vapor. In dry climates, evaporative cooling also has theadded benefit of adding humidity to the conditioned air.

A typical evaporative air conditioner has a water pump that applieswater to one or more evaporative cooling pads and a fan or blower thatblows ambient air over the pads. The air evaporates the water in thepads and thus removes heat from the air through evaporative cooling. Thecool moist air is then delivered to a building or other conditionedspace through vents and/or duct work.

Although evaporative air conditioners use less energy thanvapor-compression/absorption type systems, they suffer from severaldistinct disadvantages. For example, evaporative air conditioners oftenintroduce too much humidity into a building, which can be uncomfortableand cause walls, doors, and furniture to swell and metal components tocorrode.

Evaporative air conditioners also require large volumes of air to beintroduced into a conditioned space, thus requiring equal amounts of airinside the conditioned space to be vented out. This creates drafts andintroduces dust and other particles into the space. Air passed over theevaporative pads can be recirculated from inside the building to reducethe required amount of outside air, but air is ideally only allowed topass through the evaporative pads once because the air loses its coolingeffect as it becomes saturated with water (dry air evaporates water morequickly than damp air).

Evaporative cooling can also introduce odors into a conditioned spacebecause the evaporative pads often promote the growth of mold, mildew,and/or bacteria. The fans necessary for the constant exchange of airwithin the conditioned space can also create excessive fan noise andvibrations.

Indirect evaporative air conditioner systems solve some of theabove-described problems by utilizing heat exchangers so that thecooled, moist air never comes into direct contact with the conditionedspace. However, known indirect evaporative systems require a great dealof water and are not efficient nor practical in areas of high humidity.

SUMMARY

The present invention solves the above-described problems and provides adistinct advance in the art of evaporative type air conditioningsystems. More particularly, the present invention provides an improvedevaporative type air conditioning system that does not introduceexcessive humidity into a conditioned space; is not susceptible to mold,mildew, and/or bacteria growth; does not introduce excessive outdoor airinto the conditioned space; and is more efficient and effective thanexisting indirect evaporative air conditioning systems.

The present invention provides improved evaporative cooling with atechnology called “Accelerated Hyper-Evaporation”. As described in moredetail below, Accelerated Hyper-Evaporation creates a dense mist ofmicroscopic water droplets suspended in air then rapidly forced by apressured air blower and/or draws the mist and ambient air through ametal heat exchanger under the influence of pressurized air or a vacuumsource. This causes water in the mist to rapidly evaporate and cool theheat exchanger so the heat exchanger can cool air or any other mediumpassed over or through the heat exchanger.

An evaporative air conditioner system constructed in accordance with oneexemplary embodiment of the invention broadly comprises: a heatexchanger; a pump and nozzle assembly; an air vent; a optional pressureair blower and/or vacuum assembly; a transfer mechanism; and a controlsystem. The system may include other components that are described inthe Detailed Description section of the application below.

The heat exchanger removes heat from air delivered to the conditionedspace and isolates the air from the water used for evaporative coolingto prevent humidity from being added to the conditioned space. Anembodiment of the heat exchanger has an inlet, an outlet, and aplurality of passageways between the inlet and the outlet. Thepassageways are preferably formed from metal tubes that do not promotemold, mildew, and bacteria growth. The heat exchanger may be anair-to-vapor (ATV) type heat exchanger or a liquid-to-vapor (LTV) typeheat exchanger.

The pump and nozzle assembly provides the air and water used to cool theheat exchanger through evaporative cooling. In one embodiment, theassembly introduces and mixes pressurized air and water at the inlet ofthe heat exchanger to create a mist of water droplets suspended in air.The pump and nozzle assembly may comprise one or more high pressurewater nozzles and a water pump for delivering water at 400-50,000 psi tothe water nozzles and one or more high pressure air nozzles and an airpump or other source of pressurized air for delivering pressurized airat 25-1,000 psi to the air nozzles.

The air vent introduces pressurized or non-pressurized ambient air tothe inlet of the heat exchanger for mixing with the mist from the pumpand nozzle assembly. The amount of ambient air drawn into the heatexchanger may be regulated by a motor driven damper.

The vacuum assembly creates a partial vacuum near the outlet of the heatexchanger to rapidly draw the mist and ambient air through the heatexchanger and/or a blower may force ambient air into the inlet. Thisremoves heat from the heat exchanger through evaporative cooling.

The transfer mechanism moves air, liquid, or any other medium over orthrough the heat exchanger to cool the air or other medium. The cooledair or other medium is then used to cool a conditioned space served bythe air conditioner. Importantly, the transfer mechanism and heatexchanger do not permit the air or other medium used to cool theconditioned space to mix with the mist drawn through the heat exchangerso no humidity is added to the air delivered to the conditioned space.

The control system operates the components of the air conditioner tooptimize the performance and efficiency of the air conditioner. In oneembodiment, the control system operates the air conditioner in a firststage when ambient temperatures are below a threshold temperature and asecond stage when ambient temperatures are above the thresholdtemperature. In the second stage, the high pressure air nozzle may beactivated to provide maximum cooling. In the first stage, the air nozzlemay be turned off when less cooling is required. 1^(st) stage—lowpressure (variable) water, low speed (variable) vacuum; 2^(nd)stage—medium pressure (variable) water, medium speed (variable) vacuum;3^(rd) stage—high pressure (variable water, high pressure (variable)vacuum; and 4^(th) stage—high pressure (variable) water, high pressure(variable) vacuum, compressed air.

The above described evaporative air conditioner system provides numerousadvantages over existing air conditioner systems. For example, the airconditioner does not introduce excessive humidity into the conditionedspace; is not susceptible to mold, mildew, and/or bacteria growth; anddoes not introduce excessive outdoor air into the conditioned space. Theair conditioner system of the present invention also allows theconditioned air to be recirculated from within the conditioned space andfiltered, purified, sterilized, humidified, and/or zoned.

The air conditioner of the present invention is also more efficient andeffective than existing indirect evaporative air conditioning systems.For example, by mixing ambient air, pressurized air, and pressurizedwater at the inlet of the heat exchanger, the pump and nozzle assemblycreates a dense atomized mist that can be evaporated more quickly thanwater soaked in an evaporative pad. Then, by rapidly drawing or forcingthe mist through the heat exchanger under air and/or vacuum pressure, alarge volume of the mist quickly evaporates to rapidly remove heat fromthe heat exchanger at a significantly faster rate than evaporation inconventional evaporative type air conditioners.

An evaporative air conditioner system constructed in accordance withanother embodiment of the invention employs liquid-to-vapor (LTV) typeheat exchanger technology so that it can be self-contained and/or usedin a zoned air conditioning application. The air conditioner system ofthis embodiment broadly comprises a heat exchanger, an intermixingassembly, an air vent, a optioned pressured air blower and/or vacuumsystem, and a control system.

The heat exchanger removes heat from a liquid or other cooling mediumthat is in turn used to chill an internal or one or more remote heatexchangers. An embodiment of the heat exchanger broadly comprises ahousing and a heat transfer coil positioned in the housing. The housingis elongated and generally hollow and has a first generallyhorizontally-extending section and a second generallyvertically-extending section. A perforated support tube is positionedprimarily in the first section and has an inlet for receiving water andair from the intermixing assembly and a series of holes balancing andfor expelling the water and air therefrom. The heat transfer coil iswound around the perforated support tube and is cooled throughevaporative cooling by the water and air discharged from the perforatedsupport tube.

In some embodiments, the first housing section includes an inner wallfor enclosing the perforated support tube and the heat transfer coil andan outer wall spaced from and encircling the inner wall to provide aninsulative air gap between the inner wall and outer wall. The housingmay further have an elbow section joining the first housing section andthe second housing section. A condensation reservoir may be positionedin the elbow for collecting water that condenses from the air and fordelivering the water back to the water source.

The intermixing assembly supplies the water and air used to cool theheat exchanger and broadly comprises a housing and a nozzle positionedwithin the housing. The housing has an inlet for receiving ambient airfrom the air vent and an outlet with an inwardly tapered neck forcoupling with the perforated support tube of the heat exchanger. Aplurality of spiral vanes may be positioned within the housing forcreating turbulence in the ambient air as it passes through the housingand reduces water discharge.

The nozzle is positioned adjacent the housing outlet and has a firstinlet for connecting to a source of pressurized water; a second inletfor connecting to a source of pressurized air; and an outlet fordispensing the pressurized water and the pressurized air. Theconfiguration of the nozzle and the housing mixes the pressurized water,the pressurized air, and the ambient air to form a dense mist of tinywater droplets suspended in air near the outlet of the intermixingassembly for delivery to the intercooler heat exchanger.

The air vent introduces pressurized or non-pressurized ambient air tothe housing inlet. The air vent may be positioned anywhere and may beconnected to duct work, hoses, etc. that draw ambient air from anoutside area. The air vent may also be coupled to a motorized damper forregulating the amount of ambient air introduced in the inlet area.

The vacuum and/or forced air blower is coupled with the open end of thesecond housing section for rapidly forcing and/or drawing the water andair from the intermixing assembly, through the perforated support tube,over the heat transfer coil, and out the second housing section. Therapid transfer of the dense mist of water droplets over the heattransfer coil more quickly cools the heat transfer coil throughevaporative cooling.

The control system is similar to that one described above and maycontrol various pumps, motors, and/or valves to optimize the performanceand efficiency of the air conditioner.

An air conditioner system constructed in accordance with anotherembodiment of the invention is mostly self-contained and is thereforeespecially suited for roof-top mounting and similar applications. Anembodiment of the air conditioner system broadly comprises a housing, aheat exchanger, an air nozzle, a water nozzle, an ambient air vent, anoptional air pressure blower a vacuum assembly, a return air vent, and afan.

The housing may be of any size and shape and may be supported on wheels,casters, etc. so that the air conditioner system may be easily moved andtransported. An embodiment of the housing has a central chamber, a lowerchamber, and an upper chamber.

The heat exchanger is positioned in the central chamber of the housingand has an inlet in communication with the lower chamber, an outlet incommunication with the upper chamber, and a plurality of passagewaysbetween the inlet and the outlet. An embodiment of the heat exchangerincludes a bottom plate that defines an upper wall of the housing'slower chamber and a top plate that defines a lower wall of the housing'supper chamber. A plurality of vertically aligned holes are formed in thebottom and top plates. The heat exchanger also includes a plurality ofvertically-extending metal tubes positioned between the bottom and topplates. Each tube connects an aligned pair of holes in the bottom andtop plates and forms a passageway between the lower and upper chambersof the housing. The tubes are preferably constructed of aluminum,stainless steel, titanium or other metal.

The air nozzle and water nozzle are positioned in the lower chamber. Theair nozzle is connected to an air pump or other source of pressurizedair and the water nozzle is connected to a water pump or other source ofpressurized water to create a mist of water droplets suspended in air inthe lower chamber.

The ambient air vent introduces pressured and/or non-pressurized ambientair into the lower chamber of the housing for mixing with thepressurized air and water. As with the other embodiments of theinvention, the ambient air vent may include a motorized damper forregulating the amount of ambient air introduced into the housing.

The vacuum assembly is coupled with a vacuum port formed in the upperchamber of the housing for creating a partial vacuum in the upperchamber. This draws the mist and ambient air from the lower chamber,through the heat exchanger, and out the vacuum port to remove heat fromthe heat exchanger through evaporative cooling.

The return air vent is formed in the central chamber of the housing forreceiving air to be conditioned from a conditioned space. The fan drawsair from the return air vent through the heat exchanger to remove heatfrom the air without permitting the air to mix with the mist and ambientair drawn through the heat exchanger.

This summary is provided to introduce a selection of concepts in asimplified form that are further described in the detailed descriptionbelow. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the present invention will be apparent from thefollowing detailed description of the embodiments and the accompanyingdrawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of the present invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a schematic diagram of components of an air conditioner systemconstructed in accordance with an embodiment of the invention.

FIG. 2 is a block diagram of components of the control system of the airconditioner system.

FIG. 3 is a perspective view of components of an air conditioner systemconstructed in accordance with another embodiment of the invention.

FIG. 3A is a perspective view of an optional blower that may be coupledwith an inlet of the intermixing assembly.

FIG. 4 is a vertical sectional view of the heat exchanger assembly ofFIG. 3.

FIG. 5 is another vertical sectional view of the heat exchanger assemblyof FIG. 3.

FIG. 6 is a vertical sectional view of the intermixing assembly and aportion of the heat exchanger.

FIG. 7 is an exploded view of the nozzle in the intermixing assembly.

FIG. 8 is another exploded view of the nozzle.

FIG. 9 is an enlarged vertical sectional view of a portion of theintermixing assembly.

FIG. 10 is a vertical sectional view of an air conditioner systemconstructed in accordance with another embodiment of the invention.

FIG. 11 is a perspective view of the heat exchanger assembly in the airconditioner system of FIG. 10.

FIG. 12 is a fragmentary perspective view of one side of the airconditioner system with an optional injector block for drawing ambientair into the system.

The drawing figures do not limit the present invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description of embodiments of the inventionreferences the accompanying drawings. The embodiments are intended todescribe aspects of the invention in sufficient detail to enable thoseskilled in the art to practice the invention. Other embodiments can beutilized and changes can be made without departing from the scope of theclaims. The following detailed description is, therefore, not to betaken in a limiting sense. The scope of the present invention is definedonly by the appended claims, along with the full scope of equivalents towhich such claims are entitled.

In this description, references to “one embodiment”, “an embodiment”, or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment”, “an embodiment”, or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the present technology can include a variety of combinationsand/or integrations of the embodiments described herein.

Turning now to the drawing figures, an evaporative air conditionersystem 10 constructed in accordance with an embodiment of the inventionis illustrated. The air conditioner system 10 cools air via advancedevaporative cooling techniques and may be used to cool a house, officebuilding, or any other conditioned space. The air conditioner system 10employs a technology invented by the applicant called “AcceleratedHyper-Evaporation”. Accelerated Hyper-Evaporation creates a dense mistof microscopic water droplets suspended in air then rapidly forces ordraws the mist and ambient air through a metal heat exchanger under theinfluence of a vacuum source. This causes water in the mist to rapidlyevaporate and cool the heat exchanger so the heat exchanger can in turnchill air or any other medium passed over or through the heat exchanger(depending whether it's an ATV or LTV heat exchanger).

As shown primarily in FIG. 1, an air conditioner system 10 constructedin accordance with an exemplary embodiment of the invention broadlycomprises: a heat exchanger 12; a pump and nozzle assembly 14; an airvent 16; a pressurized air blower 17 and/or vacuum assembly 18; and atransfer mechanism 20. As shown in FIG. 2, the system 10 also includes acontrol system 22.

The heat exchanger 12 isolates water used for evaporative cooling fromthe conditioned air introduced into the conditioned space as isconventional in indirect evaporative air conditioner systems. The heatexchanger 12 and other components of the air conditioner may be enclosedwithin a cabinet, housing, or other enclosure 24. The enclosure 24defines an inlet area 26 on one side of the heat exchanger 12 and anoutlet area 28 on an opposite side of the heat exchanger.

The heat exchanger also has a plurality of passageways 30 formed betweenthe inlet area 26 and the outlet area 28 for the passage of water andair introduced in the inlet area 26. The passageways 30 are preferablyformed from metal tubes that do not promote mold, mildew, and bacteriagrowth. The tubes and hence the passageways may be between 12 and 48inches long, with a preferred length of 24 inches. The heat exchangeralso has spaces or air channels 32 transverse to the passageways 30 forthe passage of air or another medium used to cool the conditioned space.The heat exchanger may be an air-to-vapor (ATV) type heat exchanger asillustrated or a liquid-to-vapor (LTV) type heat exchanger.

The pump and nozzle assembly 14 introduces pressurized air and water tothe inlet area 26 of the heat exchanger 12 for cooling the heatexchanger. In one embodiment, the pump and nozzle assembly comprises oneor more high pressure water nozzles 34 and a water pump 36 fordelivering pressurized water to the water nozzles. The water nozzles 34are preferably positioned close to the heat exchanger 12 and dispersepressurized water across the inlet area. The pump 36 may deliver waterto the nozzles at 400-50,000 psi, with an ideal pressure of 1,000-5,000psi. The number of water nozzles 34 depends on the size of the heatexchanger 12 and the cooling needs of the conditioned space. For mosttypical applications, ten water nozzles 34 are provided.

The pump and nozzle assembly 14 also comprises one or more high pressureair nozzles 38 and an air pump 40 or other source of pressurized air fordelivering pressurized air to the air nozzles. The air nozzles 38 arepreferably positioned below the water nozzles 34 and angled upwardly todirect pressurized air into the streams of water provided by the waternozzles 34. This mixes the air and water into a dense mist ofmicroscopic water droplets suspended in air. The air pump 40 may deliverair to the nozzles at 25-1,000 psi, with an ideal pressure of 100-300psi. As with the water nozzles 34, the number of air nozzles 38 dependson the size of the heat exchanger 12 and the cooling needs of theconditioned space. In one embodiment, ten air nozzles 38 are provided.

The air vent 16 introduces either pressurized or non-pressurized ambientair to the inlet 26 of the heat exchanger 12 for mixing with the mistand evaporating the water in the mist. The air vent 16 may be positionedanywhere on the inlet area 16 side of the heat exchanger 12 and may beconnected to duct work, hoses, etc. that draw ambient air from anoutside area. The air vent 16 may also be coupled to a motorized damper42 for regulating the amount of ambient air introduced in the inlet area26. An optional pressure air blower 17 may be provided to force ambientair into the air vent 16.

The vacuum assembly 18 creates a partial vacuum near the outlet area 28of the heat exchanger 12 to rapidly draw the mist and ambient airthrough the passageways 30 and out of the enclosure 24. As the mist andambient air is drawn through the heat exchanger 12, the ambient airevaporates the water suspended in the mist to remove heat from the heatexchanger 12 through evaporative cooling.

In one embodiment, the vacuum assembly 18 comprises one or more fans,blowers, etc., that are connected to discharge ports 44 or vents nearthe outlet area of the heat exchanger. The fans, blowers, etc. aredriven by one or more motors 46. The motor or motors 46 may bemulti-speed or variable speed motors so that the control system 22 mayselect the optimum level of vacuum pressure for a given cooling load andcurrent ambient temperatures and humidity. Applicant has discovered thata vacuum pressure of 0.01 to 15 in Hg is desirable for mostapplications, with a vacuum pressure nearer the lower range for lowcooling requirements and nearer the higher range for higher coolingrequirements.

A vacuum equalizer plate 47 with a plurality of equally-sized and spacedopenings may be positioned between the vacuum discharge ports 44 and theoutlet area 28 of the heat exchanger 12 to equalize the vacuum pressureacross all the heat exchanger passageways 30. A moisture extractor 48may be positioned below the vacuum equalizer plate 47 to extractmoisture from the air pulled through the heat exchanger and to directthe moisture back to the inlet area 26 of the heat exchanger to reducethe water requirements of the air conditioner system.

A condensation reservoir or sump may be provided in the bottom of theenclosure 24 for collecting water condensation from the inlet area 26and re-introducing the water to the pump 36.

The transfer mechanism 20 moves air, liquid, or other medium through thepassageways 32 of the heat exchanger 12 without permitting the air orother medium to mix with the mist drawn through the passageways 30 ofthe heat exchanger. This removes heat from the air passing over the heatexchanger without adding humidity to the air. The transfer mechanism 20may be a blower, fan, pump, or any other similar mechanism and may bedriven by one or more motors 50.

The control system 22 operates the other components of the airconditioner system 10 to optimize the performance and efficiency of thesystem. An embodiment of the control system may include a controller 52,one or more external sensors 54, one or more internal sensors 56, a userinterface 58, and circuitry 60 coupled with the pumps and motors 36, 40,42, 46, 50.

The controller 52 may be a microcontroller, application specificintegrated circuit (ASIC), computer, or any other computing device orcontrol circuit capable of implementing logical functions. Thecontroller 52 may be pre-programmed at the factory to operate the airconditioner system in a particular manner based on data received formthe external sensors 54 and internal sensors 56 or may beuser-configured with the user interface 58.

The external sensors 54 may comprise a thermostat, enthalpy sensor,humidity sensor, and/or other environmental sensors for sensing outsideambient temperatures and humidity levels. Likewise, the internal sensors56 may comprise a thermostat, humidity sensor, and/or otherenvironmental sensors for sensing temperatures and humidity levelsinside the conditioned space. The user interface 58 may include anycombination of buttons, switches, keypads, touchscreen displays, etc.and may be incorporated in the controller 52 or be a stand-alone device.

The circuitry 60 may include relays, switches, variable speed drives, orother components capable of controlling the pumps 36, 40 connected tothe water nozzles 34 and air nozzles 38 and the motors 42, 46, 48connected to the air vent 16, the optional forced air blower the vacuum18, and the transfer mechanism 20. The circuitry 60 communicates withand is controlled by the controller 52.

In one embodiment, the controller 52 receives data representative of anambient outside temperature and humidity level from the external sensors54, data representative of an inside temperature and humidity level fromthe internal sensors 56, and a desired set point temperature and/orhumidity level from the user interface 58, and then controls operationof the air conditioner to achieve optimum cooling and efficiency basedon this data. In some embodiments, the control system may operate theair conditioner in a number of stages. For example, when the outsideenvironment is extremely hot and/or humid and a user has called for alow inside temperature, the controller 52 may: (1) operate the motors46, 50 at full speed to provide maximum vacuum and/or blower pressure atthe outlet area 28 of the heat exchanger and maximum air speed acrossthe heat exchanger; (2) open the vents 16 completely to provide amaximum amount of ambient air at the inlet of the heat exchanger; (3)operate the air pumps 40 at maximum speed to provide maximum airpressure to the air nozzles 38; and (4) operate the water pumps 36 atfull speed to provide maximum water pressure at the water nozzles 34.This creates maximum cooling of the heat exchanger 12 until a desiredset point temperature is reached within the conditioned space.

In contrast, when the outside environment is less hot and/or humid, thecontroller 52 may: (1) operate the motors 46, 50 at a lower speed toprovide less vacuum and/or blower pressure at the outlet of the heatexchanger and a lower air speed across the heat exchanger; (2) open thevents 16 only partially to provide less ambient air at the inlet of theheat exchanger; (3) operate the air pumps at a reduced speed to providea lower air pressure to the air nozzles 38; and (4) operate the waterpumps at a reduced speed to provide less water pressure at the waternozzles. This creates a lower rate of cooling of the heat exchangeruntil a desired set point temperature is reached within the conditionedspace.

In another embodiment, the control system 22 operates the airconditioner system 10 in a first stage when ambient temperatures arebelow a threshold temperature and a second stage when ambienttemperatures are above the threshold temperature. The control system 22activates the high pressure air nozzle in the second stage but not inthe first stage.

In another embodiment, the control system operates the air conditionerin four stages, including: 1^(st) stage—low pressure (variable) water,low speed (variable) vacuum and/or blower; 2^(nd) stage—medium pressure(variable) water, medium speed (variable) vacuum and/or blower; 3^(rd)stage—high pressure (variable water, high pressure (variable) vacuumand/or blower; and 4^(th) stage—high pressure (variable) water, highpressure (variable) vacuum and/or blower, compressed air.

An evaporative air conditioner system 100 constructed in accordance withanother embodiment of the invention will now be described with referenceto FIGS. 3-9. The air conditioner system 100 employs liquid-to-vapor(LTV) heat exchanger technology so that it can be self-contained or usedin a zoned air conditioning application. An embodiment of the airconditioner system 100 broadly comprises a heat exchanger 102, anintermixing assembly 104, an air vent 106, optional forced air and/or avacuum assembly 108, and a control system.

The heat exchanger 102 removes heat from a liquid or other coolingmedium which is then pumped to an internal heat exchanger and/or one ormore remote heat exchangers to remove heat from air delivered to one ormore zones of a conditioned space. An embodiment of the heat exchanger102 is best illustrated in FIGS. 4-6 and comprises a generally hollowhousing 112 and a heat transfer coil 114 supported on a perforatedsupport tube 116 positioned in the housing.

An embodiment of the housing 112 is generally J-shaped or L-shaped andhas a generally circular cross section. The housing has a firstgenerally horizontally-extending section 118, a second generallyvertically-extending section 120, and an adjoining elbow section 122. Insome embodiments, the first housing section 118 includes an inner wallfor enclosing the perforated support tube 116 and the heat transfer coil114 and an outer wall spaced from and encircling the inner wall toprovide an insulative air gap between the inner wall and outer wall.

The housing 112 may be constructed of any suitable materials such asmetal, plastic, or composites and may be of various sizes to accommodatevarious different cooling levels. In one embodiment, the first housingsection 118 is 12 to 72 inches long and has a diameter of 6 to 20inches, and the second housing section 120 is 12 to 72 inches long andhas a diameter of 6 to 20 inches.

The perforated support tube 116 is positioned primarily in the firsthousing section 118 and, as best illustrated in FIG. 6, has an inlet 130aligned with the intermixing assembly 104. The support tube 116 has aseries of holes spaced along its length for expelling the water and airreceived from the intermixing assembly 104 and a capped or otherwiseclosed end 132 (see FIG. 4) adjacent the elbow 122 to force the waterand air out the holes.

The support tube 116 may be formed of any suitable materials and may beof various sizes. In one embodiment, the support tube 116 is formed froma metal or plastic pipe that is 12 to 72 inches long and 2 to 20 inchesin diameter and that has approximately 100 to 10,000 perforated holes of3/32 to ½ inches diameter each.

The heat transfer coil 114 is wound around the perforated support tube116 and carries a liquid or other medium to be cooled by the heatexchanger 102. An embodiment of the heat transfer coil 114 is in theshape of a cylindrical helix and is formed from aluminum or other metaltubing that is 36 to 500 inches long when not wound on the support tube116 and ¼ to 1 inch in diameter.

As best shown in FIGS. 3 and 4, the heat transfer coil 114 has an inlet134 that serves as a fluid return for receiving warm water or othermedium that has already been used to cool one or more remote heatexchangers in the air conditioner system. The heat transfer coil 114also has an outlet 136 that delivers chilled water or other medium tothe remote heat exchangers. The air conditioner system may also includevarious pumps, valves, tanks, and piping connected to the heat transfercoil 114 for distributing the cooling medium to and from the remote heatexchangers.

The intermixing assembly 104 will now be described in more detail withreference primarily to FIG. 6. The intermixing assembly 104 supplieswater and air to the heat exchanger 102 to cool the heat transfer coil114 through evaporative cooling and broadly comprises a housing 138 anda nozzle 140 positioned in the housing. The housing 138 may beconstructed of any suitable materials such as metal, plastic, orcomposites and may be of various shapes and sizes. One embodiment of thehousing 138 is tubular and is between 8 and 48 inches long and 4 and 14in diameter.

The housing 138 has a first end 142 that may define the air vent 106 anda second end with an inwardly tapered neck 144 that defines an outlet146 for coupling with the inlet 130 of the perforated support tube 116.The reduced diameter neck 144, in combination with the vacuum assembly108 described below, creates a pressurized vortex region near the outlet146 of the intermixing assembly that aids in the mixing of the air andwater flowing through the intermixing assembly. A plurality of spiralvanes 148 may be positioned along the length of the housing 138 forcreating turbulence in the ambient air as it passes through the housing138 to further aid in the mixing of the air and water.

The nozzle 140 is positioned in the reduced diameter neck 144 of thehousing 138 and dispenses pressurized water and air that is mixed withthe ambient air from the vent 106. As best illustrated in FIG. 9, thenozzle 140 has a first inlet 150 for connecting to a tube or pipe 152that is in turn connected to a water pump or other source of pressurizedwater; a second inlet 154 for connecting to a tube or pipe 156 that isin turn connected to an air pump or other source of pressurized air; andan outlet 158 for dispensing the pressurized water and the pressurizedair to the outlet 146 of the intermixing assembly.

An exploded view of the nozzle 140 is shown in FIGS. 7 and 8. As shown,the nozzle 140 includes mating front and rear caps 160, 162, an airdistributor ring 164 sandwiched between the caps, and a water nozzle orsprayer 166 extending through the outlet 158 in the front cap. Thecomponents of the nozzle may be constructed of any suitable materialssuch as hardened plastic or metal.

The front cap 160 is dome-shaped and has an opening that defines theoutlet 158 of the nozzle. The inside wall of the front cap also has anumber of vanes 168 to create turbulence in the pressurized air flowingthrough the nozzle.

The rear cap 162 is attached to the front cap 160 as best shown in FIG.9 and includes openings for passage of the tubes 152, 156 as best shownin FIG. 7. The rear cap 162 also has several annular slots for receivingseveral sealing O-rings 170, 172.

The air distributor ring 164 fits between the front and rear caps 160,162 and has a central passageway 174 through which the water tube 152extends. The air distributor ring 164 also has an annular chamber 176that receives and supports an air filter 178. A plurality of air holes180 are formed in one wall of the chamber 176 for dispensing air aroundthe water nozzle 166 as described below.

The water nozzle or sprayer 166 is attached to the water tube 152 anddispenses water out of the nozzle through the outlet 158 in the frontcap 160. The water nozzle 152 is positioned inside the air holes 180 sothat the nozzle assembly dispenses a central stream of pressurized watersurrounded by a concentric stream of pressurized air. The inward taperof the front cap 160 directs the pressurized air toward the center ofthe nozzle so that the air stream intersects the water stream about1/16-2 inches in front of the water nozzle. The pressurized air thenmixes with the ambient air and the pressurized water to form a densemist of water droplets suspended in air in the vicinity of the outlet146 of the intermixing assembly. This dense mist allows for moreeffective evaporative cooling as described herein.

One or more pumps, valves, etc. deliver water to the nozzle 166 at400-50,000 psi, with an ideal pressure of 1,000-5,000 psi. Likewise, oneor more air pumps, valve, etc. deliver air to the annular air chamber176 at 25-1,000 psi, with an ideal pressure of 100-300 psi.

The air vent 106 introduces either pressurized or non-pressurizedambient air to the intermixing assembly 104. The air vent is shown inthe first end of the intermixing assembly housing 138 but may bepositioned anywhere and may be connected to duct work, hoses, etc. thatdraw ambient air from an outside area. The air vent 106 may also becoupled to a motorized damper for regulating the amount of ambient airintroduced in the inlet area. An air blower 107 may provide pressurizedair to the air vent 106 as shown in FIG. 3 a to increase the flow ofambient air through the intermixing assembly and for forcing the ambientair and mist through the heat exchanger.

The vacuum assembly 108 is coupled with the upper open end of the secondhousing section 120 and creates a partial vacuum in the heat exchanger.This rapidly draws the mist and ambient air from the intermixingassembly 140 into the inlet 130 of the perforated support tube 116,through and out the support tube, over the heat transfer coil 114, andthrough the second housing section 120. As the mist and ambient air israpidly drawn or forced through the heat exchanger under vacuum orblower pressure, the ambient air evaporates the water suspended in themist to remove heat from the heat transfer coil through evaporativecooling.

In one embodiment, the vacuum assembly 108 comprises one or more fans,blowers, etc., that are connected to the open end of the second housingsection. The fans, blowers, etc. may be driven by one or moremulti-speed or variable speed motors so that the control system mayselect the optimum level of vacuum pressure for a given cooling load andcurrent ambient temperatures and humidity. Applicant has discovered thata vacuum pressure of 0.01 to 15 in Hg is desirable for mostapplications, with a vacuum pressure nearer the lower range for lowcooling requirements and nearer the higher range for higher coolingrequirements.

A vacuum equalizer plate with a plurality of equally-sized and spacedopenings may be positioned below the vacuum to equalize the vacuumpressure across the second housing section. A plurality of moistureextractors 182 are positioned primarily in the second section of thehousing and are operable to extract water from the air before it isdischarged from the second housing section. Water in the air that is notevaporated in the first housing section condenses on the bottom surfacesof the moisture extractors and drips into the elbow section 122 of thehousing.

As best shown in FIGS. 4 and 5, a condensation reservoir 184 may bepositioned in the elbow 122 for collecting water that condenses from theair passing through the second housing. Piping 186 and a pump connectedwith the condensation reservoir 184 may then pump the condensed waterback to the nozzle 140 to reduce the water requirements of the nozzle.The control system may operate the pump whenever the reservoir 184 isfull. When the pump for the reservoir 184 is being operated, the controlsystem may shut down other water pumps feeding pressurized water to thenozzle 140.

An embodiment of the control system may be substantially identical tothe control system illustrated in FIG. 2 and is therefore not describedin detail again. The control system optimizes the performance andefficiency of the heat exchanger and intermixing assembly and matchestheir operation to a desired cooling level or load.

An evaporative air conditioner system 200 constructed in accordance withanother embodiment of the invention will now be described with referenceto FIGS. 10-12. The air conditioner system 200 is mostly self-containedand is therefore especially suited for rooftop mounting applications andother similar applications.

As best illustrated in FIG. 10, an embodiment of the air conditionersystem 200 broadly comprises a housing 202, a heat exchanger 204, a pairof air nozzles 206, a pair of water nozzles 208, one or more vacuumports 212, a vacuum assembly 214, a return air vent 216, and a fan 218.An optional injector nozzle block 219 is shown in FIG. 12. Ambient airflows around and through the injector block 219 and into the housing202. The air conditioner system 200 may also include or be coupled witha control system for optimizing performance in the system as describedbelow.

The housing 202 may be constructed of any suitable materials and be ofany size to accommodate the other components of the air conditioner. Thehousing may be supported on wheels, caster, etc. so that it can beeasily moved and transported. As shown in FIG. 10, an embodiment of thehousing has a central chamber 220, a lower chamber 222, and an upperchamber 224. The floor of the lower chamber 222 may be negatively slopedapproximately 2% from right to left as viewed from the perspective ofFIG. 10 for drainage purposes.

The heat exchanger 204 is positioned in the central chamber 220 of thehousing and has an inlet in communication with the lower chamber 222 andan outlet in communication with the upper chamber 224. An embodiment ofthe heat exchanger 204 is shown in FIG. 11 and includes a bottom plate226 that defines an upper wall of the lower chamber 222 and a top plate228 that defines a lower wall of the upper chamber 224. A plurality ofvertically aligned holes are formed in the bottom and top plates. Theheat exchanger also includes a plurality of vertically-extending metaltubes 230 positioned between the bottom and top plates. Each tubeconnects an aligned pair of holes in the bottom and top plates and formsa passageway between the lower and upper chambers 222, 224 of thehousing. As best shown in FIG. 11, several of the tubes may be flushwith the top surface of top plate 228 so that any condensation can draininto the lower chamber 222 where it can be recirculated.

The tubes 230 are preferably constructed of aluminum, stainless steel,titanium or other metal and are 12 to 48 inches long and 3/16 to 1.5inches in diameter. Embodiments of the heat exchanger may includebetween 100-5,000 metal tubes. A particular embodiment of the heatexchanger includes approximately 250-350 metal tubes that are spacedbetween ⅛ inch to 1 inch apart.

The air nozzles 206 and the water nozzles 208 are positioned in thelower chamber 222 and are operable for introducing pressurized air andwater in the lower chamber. This creates a mist of water dropletssuspended in air in the lower chamber for cooling the heat exchangerthrough evaporative cooling.

The water nozzles 208 are preferably positioned near the top of thelower chamber and disperse pressurized water horizontally across thelower chamber. A pump may deliver water to the nozzles at 400-50,000psi, with an ideal pressure of 1,000-5,000 psi. The pump may be locatedremotely or may be mounted in the housing so that the air conditionersystem only needs to be connected to a water supply. The number of waternozzles 208 depends on the size of the heat exchanger 204 and thecooling needs of the conditioned space. For most typical applications,ten water nozzles 208 are provided.

The air nozzles 206 are preferably positioned below the water nozzles208 and angled upwardly to direct pressurized air into the streams ofwater provided by the water nozzles 208. This mixes the air and waterinto a dense mist of microscopic water droplets suspended in air. An airpump may deliver air to the nozzles at 25-1,000 psi, with an idealpressure of 100-300 psi as with the water pump, the air pump may bemounted remotely or within the housing. The number of air nozzles 206depends on the size of the heat exchanger 204 and the cooling needs ofthe conditioned space. In one embodiment, ten air nozzles 206 areprovided.

The ambient air vents 210 are positioned in the lower chamber 222 forintroducing non-pressurized ambient air to the lower chamber for mixingwith the pressurized air and water. A damper may be mounted in theambient air vent for regulating an amount of ambient air drawn into thelower chamber.

The vacuum ports 212 are formed in the upper chamber 224 and permit airto be evacuated from the housing. The vacuum assembly 214 is coupledwith the vacuum ports for creating a partial vacuum in the upper chamber224 to draw the mist and ambient air from the lower chamber 222 andthrough the heat exchanger 204 to remove heat from the heat exchangerthrough evaporative cooling.

In one embodiment, the vacuum assembly 214 comprises one or more fans,blowers, etc., that are driven by one or more motors. The motor ormotors may be multi-speed or variable speed motors so that a controlsystem may select the optimum level of vacuum pressure for a givencooling load and current ambient temperatures and humidity. Applicanthas discovered that a vacuum pressure of 0.01 to 15 in Hg is desirablefor most applications, with a vacuum pressure nearer the lower range forlow cooling requirements and nearer the higher range for higher coolingrequirements.

A condensation reservoir may be positioned or formed in the lowerchamber 222 of the housing for collecting water condensation. Acondensation pump may be coupled with the condensation reservoir forpumping the water condensation to the water nozzles 208.

A vacuum equalizer plate 232 with a plurality of equally-sized andspaced holes may be positioned in the upper chamber 224 between thevacuum ports 212 and the heat exchanger 204 for partially equalizingvacuum pressure across the outlet of the heat exchanger.

A moisture extractor 234 may be positioned in the upper chamber 224between the vacuum port 212 and the heat exchanger 204 for removingmoisture from air before it is discharged from the vacuum port. Themoisture extractor delivers the extracted moisture to the condensationreservoir in the lower chamber.

The return air vent 216 is formed in one side of the central chamber forreceiving air to be conditioned from a conditioned space. The fan 218 ispositioned in a second side of the central chamber for drawing the airfrom the return air vent and through the heat exchanger to remove heatfrom the air without permitting the air to mix with the mist and ambientair drawn through the heat exchanger.

The air conditioner system may also include a control system similar tothe control systems described above.

The above described evaporative air conditioner systems 10, 100, 200provide numerous advantages over existing air conditioner systems. Forexample, the air conditioners 10, 100, 200 do not introduce excessivehumidity into a conditioned space; are not susceptible to mold, mildew,and/or bacteria growth; and do not introduce excessive outdoor air intothe conditioned space. The air conditioner systems also allow theconditioned air to be recirculated from within the conditioned space andfiltered, purified, sterilized, humidified, and/or zoned.

The air conditioners are also more efficient and effective than existingindirect evaporative air conditioning systems. For example, the airconditioning systems create a dense atomized mist that can be evaporatedmore quickly than water soaked in evaporative pads. Also, by rapidlydrawing the mist through the heat exchangers under vacuum pressure, alarge volume of the mist quickly evaporates to rapidly remove heat fromthe heat exchangers at a significantly faster rate than evaporation inconventional evaporative type air conditioners.

Although the invention has been described with reference to thepreferred embodiment illustrated in the attached drawing figures, it isnoted that equivalents may be employed and substitutions made hereinwithout departing from the scope of the invention as recited in theclaims. For example, the specific components of the air conditionersystem 10 described and illustrated herein may be replaced and/orsupplemented with equivalent components.

Having thus described the preferred embodiment of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:
 1. A self-contained evaporative air conditioner systemcomprising: a partially enclosed housing having a central chamber, alower chamber, and an upper chamber; a heat exchanger positioned in thecentral chamber and having an inlet in communication with the lowerchamber, an outlet in communication with the upper chamber, and aplurality of passageways between the inlet and the outlet; an air nozzleand a water nozzle positioned in the lower chamber for introducingpressurized air and water in the lower chamber to create a mist of waterdroplets suspended in air; an air nozzle and a water nozzle positionedin the lower chamber for introducing pressurized air and water in thelower chamber to create a mist of water droplets suspended in air; anambient air vent for introducing non-pressurized ambient air to thelower chamber for mixing with the pressurized air and water; a vacuumport formed in the upper chamber; a vacuum assembly coupled with thevacuum port for creating a partial vacuum in the upper chamber to drawthe mist and ambient air from the lower chamber through the heatexchanger to remove heat from the heat exchanger through evaporativecooling; a return air vent formed in the central chamber for receivingair to be conditioned from a conditioned space; and a fan for drawingair from the return air vent through the heat exchanger to remove heatfrom the air without permitting the air to mix with the mist and ambientair drawn through the heat exchanger.
 2. The air conditioner system ofclaim 1, further comprising: a water pump for delivering pressurizedwater to the water nozzle; and an air pump for delivering pressurizedair to the air nozzle.
 3. The air conditioner system of claim 2, furthercomprising a damper mounted in the ambient air vent for regulating anamount of ambient air drawn into the lower chamber.
 4. The airconditioner system of claim 1, further comprising a condensationreservoir positioned in the lower chamber for collecting watercondensation.
 5. The air conditioner system of claim 4, furthercomprising a condensation pump coupled with the condensation reservoirfor pumping the water condensation to the water nozzle.
 6. The airconditioner system of claim 1, wherein the heat exchanger comprises: abottom plate that defines an upper wall of the lower chamber, the bottomplate having a plurality of holes formed therein; a top plate thatdefines a lower wall of the upper chamber, the top plate having aplurality of holes vertically aligned with the holes in the bottomplate; and a plurality of vertically-extending metal tubes positionedbetween the bottom and top plates and connecting aligned pairs of holesin the bottom and top plates.
 7. The air conditioner system of claim 1,further comprising a control system for operating the air conditioner ina first stage when ambient temperatures are below a thresholdtemperature and a second stage when ambient temperatures are above thethreshold temperature, wherein the control system activates the highpressure air nozzle in the second stage but not in the first stage. 8.The air conditioner system of claim 1, further comprising a vacuumequalizer plate positioned in the upper chamber between the vacuum portand the outlet of the heat exchanger for partially equalizing vacuumpressure across the outlet of the heat exchanger.
 9. The air conditionersystem of claim 4, further comprising a moisture extractor positioned inthe upper chamber between the vacuum port and the outlet of the heatexchanger for removing moisture from air before it is discharged fromthe vacuum port.
 10. The air conditioner system of claim 9, wherein themoisture extractor delivers the extracted moisture to the condensationreservoir in the lower chamber.
 11. A self-contained evaporative airconditioner system comprising: a partially enclosed housing having acentral chamber, a lower chamber, and an upper chamber; a heat exchangerpositioned in the central chamber and having an inlet in communicationwith the lower chamber and an outlet in communication with the upperchamber, the heat exchanger comprising: a bottom plate that defines anupper wall of the lower chamber, the bottom plate having a plurality ofholes formed therein; a top plate that defines a lower wall of the upperchamber, the top plate having a plurality of holes vertically alignedwith the holes in the bottom plate; and a plurality ofvertically-extending metal tubes positioned between the bottom and topplates and connecting aligned pairs of holes in the bottom and topplates, the lower open ends of the tubes defining the inlet to the heatexchanger and the upper open ends of the tubes defining the outlet tothe heat exchanger; an air nozzle and a water nozzle positioned in thelower chamber for introducing pressurized air and water in the lowerchamber to create a mist of water droplets suspended in air; an airnozzle and a water nozzle positioned in the lower chamber forintroducing pressurized air and water in the lower chamber to create amist of water droplets suspended in air; an ambient air vent positionedin the lower chamber for introducing non-pressurized ambient air to thelower chamber for mixing with the pressurized air and water; a vacuumport formed in the upper chamber; a vacuum assembly coupled with thevacuum port for creating a partial vacuum in the upper chamber to drawthe mist and ambient air from the lower chamber through the heatexchanger to remove heat from the heat exchanger through evaporativecooling; a return air vent formed in one side of the central chamber forreceiving air to be conditioned from a conditioned space; and a fanpositioned in a second side of the central chamber for drawing the airfrom the return air vent and through the heat exchanger to remove heatfrom the air without permitting the air to mix with the mist and ambientair drawn through the heat exchanger.
 12. The air conditioner system ofclaim 11, further comprising: a water pump for delivering pressurizedwater to the water nozzle at 400-50,000 psi; and an air pump fordelivering pressurized air to the air nozzle at 25-1,000 psi.
 13. Theair conditioner system of claim 12, further comprising a damper mountedin the ambient air vent for regulating an amount of ambient air drawninto the lower chamber.
 14. The air conditioner system of claim 11,further comprising a condensation reservoir positioned in the lowerchamber for collecting water condensation.
 15. The air conditionersystem of claim 14, further comprising a condensation pump coupled withthe condensation reservoir for pumping the water condensation to thewater nozzle.
 16. The air conditioner system of claim 11, furthercomprising a control system for operating the air conditioner in a firststage when ambient temperatures are below a threshold temperature and asecond stage when ambient temperatures are above the thresholdtemperature, wherein the control system activates the high pressure airnozzle in the second stage but not in the first stage.
 17. The airconditioner system of claim 11, further comprising a vacuum equalizerplate positioned in the upper chamber between the vacuum port and theoutlet of the heat exchanger for partially equalizing vacuum pressureacross the outlet of the heat exchanger.
 18. The air conditioner systemof claim 1, further comprising a moisture extractor positioned in theupper chamber between the vacuum port and the outlet of the heatexchanger for removing moisture from air before it is discharged fromthe vacuum port.
 19. The air conditioner system of claim 9, wherein themoisture extractor delivers the extracted moisture to the condensationreservoir in the lower chamber.